With continuous development of display technology, oxide thin film transistors have been increasingly used widely due to the characteristics of high electron mobility, low fabricating temperature, good uniformity, transparency to visible light, low threshold voltage and the like.
In manufacturing of an oxide thin film transistor in the prior art, since an oxide active layer of the oxide thin film transistor is made of metal oxide, it is poor in stability, and prone to influence by oxygen, hydrogen and water in etching environment. Thus, in order to prevent the oxide active layer from being affected in etching of a source and a drain of the oxide thin film transistor, an etch stop layer (ESL) is added for protecting the oxide active layer.
The inventor found at least the following problems in the prior art. Since the etch stop layer is added, that is, a step of fabricating process of the oxide thin film transistor is added, if fabrication of the etch stop layer is not controlled properly in this case, for example, if the thickness of the etch stop layer fabricated is non-uniform, properties of the oxide thin film transistor may be affected. Thus, not only the manufacturing process of the oxide thin film transistor becomes complicated and the manufacturing cost is increased, but also the production capacity and yield of the array substrate manufactured are reduced. To solve the problem that the oxide thin film transistor in the prior art needs to be provided with the etch stop layer, a crystalline oxide active layer is generally adopted as the oxide active layer of the oxide thin film transistor, but the crystallizing temperature is very high and is very likely to affect other film layers, and thus lowing the crystallizing temperature of the oxide active layer is highly anticipated for applications of the oxide thin film transistor.